Three A-list, top-draw actors sat in front of a packed New York theater, spotlighted in front of a just-darkened big screen. They were speaking to the audience at a question and answer session at the premiere of their latest film -- two box office-lock funnymen and an Oscar winning actress -- all heaping praise on the co-directors of the project. And as the plaudits flowed, with commendations to the filmmakers for their vision and approach, the director in town for the show worked to contain a smile, straightened his skinny tie, shuffled his old Chucks and interjected here and there with self-deprecating jokes.

After all, situational improv is what Mark Duplass does best, and sticking with that long take, real-time style has already paid off big time.

The very definition of a modern multi-hyphenate -- an actor, writer, director, producer and genre-shaper -- Duplass has been making films with his brother Jay since they were children growing up in Louisiana. That's where their new movie, Jeff, Who Lives at Home is set, and while no, the film that features Jason Segel and Ed Helms playing two lost brothers is not based on the Duplass' personalities or relationship, it's quite fitting that the small story about great destiny was made on what was their original home turf: they may now live in Los Angeles, but Hollywood has had to come to them.

The Duplass' first film, 2005's The Puffy Chair, was a road trip flick based on a very simple premise: a guy goes to pick up a pink recliner and give it to his dad as a birthday gift. Mark played Josh, who takes along his girlfriend (played by his real life wife, Katie Aselton) and brother on the trip to retrieve and then deliver the raggedy piece of furniture.

There are no car chases, explosions or drunk hijinks; the drama is derived from the breakdown in the relationships as the trip progresses. With close ups, extended hand held shots, improvised dialogue and a cast made up of friends, the movie set the template for their filmmaking style and helped define the micro indie genre that came to be known as mumblecore.

It cost only $15,000 to make and had no wide release, but the effort caught the attention of major studios, who began offering the brothers lucrative deals to jump aboard their labels.

"It was surprising to us because it was such a small movie, but I think we discovered that for whatever reason, producers and studios, they feel like there are no good filmmakers out there and they will tell you that over and over again," Duplass told The Hollywood Reporter a few days after the Jeff premiere. "We got surprisingly big offers to direct some movies early on but nothing felt quite right."

It was their desire to execute their own vision that kept them from jumping to the studios; they had largely been asked to swoop in and try to rush fixes on troubled projects with $40+ million budgets and a movie star tenuously attached. "Basically everyone understood that the movie was going to be bad but it would probably make money," Duplass remembered. "We believed that making a bad movie is not only bad for your career but bad for your spirit."

Still, saying no to those opportunities wasn't exactly easy for the young filmmakers. "It was heartbreaking to turn down the paycheck at the time because we were broke," he said. "I guess we picked the more organic approach, slowly increasing budgets and scope of what we want to do."

And so the brothers continued to work on their terms, writing the first draft of Jeff and then releasing the horror send-up Baghead in 2008. Thought that film was a big shift in subject matter, the film maintained the long rolling takes, narrative-based improv and focus on the interpersonal drama that made The Puffy Chair so compelling.

More acting work came along, too, as Mark grabbed a major role on FX's fantasy sports buddy comedy The League and appeared in a number of lauded microbudget films. Those included the off-beat animated film Mars and director Lynn Shelton's very real-life Humpday, which centered on two straight friends (the other, played by Joshua Leonard) who drunkenly agree to have sex with each other on camera for an art-porn film festival. Talk about the interpersonal.

By the time 2010 came around, the brothers were reaching their creative stride -- and again, Hollywood was taking notice. They co-wrote and directed Cyrus, their biggest, most star-studded project yet, signing up John C. Reilly, Marisa Tomei and Jonah Hill to tell the story of a teenager who fights against his single mom's budding romance.

There always seems to be a broader version of the Duplass' movies, and with Hill, who stars this coming weekend in 21 Jump Street, and Reilly, who has co-starred in a number of Will Ferrell films, it would have been easy to fill Cyrus with gratuitous sex jokes and slapstick set pieces. It may have even worked, given the talent involved. But again, they turned their cheek at the broad, opting to go with their trademark shots and favored subtle interactions.

"We love faces and we love personal inter-dynamics and the sort of comedic and tragic that family members and loved ones do to each other," Duplass explained. "That's what we're obsessed with, and even though we have been afforded budgets, we still love our close-ups."

Their continued dedication to the style has resulted in a finely honed trademark of sorts, but in an industry that loves to quantify, product test and focus group every aspect of its product, it's also created a bit of an inconvenience. Despite existing more and more in the mainstream, they can't shake off that niche -- and perhaps meaningless -- label.

"I think it was nice in 2005 that the New York Times decided to write about $10,000 movies, and at that point I was happy to have them call it whatever the f--k they wanted to call it, but I think the term mumblecore has outlived its usefulness at this point," Duplass said. "And it almost to me feels exclusionary. I'm not making mumblecore films, I'm making movies that I want to invite everybody to come and see, and people don't mumble in my movies. There's a lot of heavy plotting in Jeff, Who Lives at Home, so I certainly wouldn't call Jeff a mumblecore movie at all."

In fact, Jeff, with its bi-coastal premieres and Paramount pedigree, will be their widest and most heavily marketed release to date. And if it isn't mumblecore, it's still definitely still core Duplass, scaling down and inverting the sort of film they turned down making six years ago. Segel plays a sloppy stoner, which is no great stretch for him given his roles in hit (and quite funny) Judd Apatow projects like Knocked Up and Freaks and Geeks, but there is a lot buried beneath the smoke and hoodie in this one.

"I think when you look at the trailer for Jeff, you're going to make a snap judgment. You're going to say, 'Oh, this is a man-child stoner comedy, I've seen this.' But we encourage people to come see the movie because we're not trying to tell that story, we're trying to tell the story about a guy who is a real believer, and a guy who thinks the universe has something great in store for him," Duplass said, distinguishing his film from the standard Cheech & Chong variety. "I see him as someone who is the opposite of a slacker. He is a thinker and a neo-philosopher and he's waiting like a coiled spring for the moment to discover his destiny and the movie is about that day in his life."

Again, there is a small plot packed with bigger meaning, as Jeff starts out running an errand for his mom and follows a few broadly interpreted clues to a side adventure that he thinks will uncover his true fate. Along the way he meets up with Helms, who plays his older, maritally-troubled brother Pat (Helms). The pair, whose relationship is fraught with resentment, discovers that Pat's wife (Judy Greer) is cheating on him, setting up a chase that provides plenty of opportunities for conflict.

For Segel, the role was a difficult yet rewarding experience.

"All they demanded of you, which is the biggest challenge of all time, is just to be honest," the actor said at the post-screening Q&A. "They didn't want you to try to be super funny, they just wanted you to be honest. And one of the great tricks they have is, because they shoot on digital, they can just point the camera at you and let it roll, and there is this unspoken sort of challenge that is like, well you claim you're an actor, let's see. And I didn't know if I could do that, I had no idea."

Susan Sarandon, who plays the brothers' equally confused mother, said that she was plain scared of the improvisation, and both she and Helms told THR that they had to raise their games to make the film work.

It's probably a mix of sound decision making and irony that has delivered the Duplasses such big name stars; not only did their earlier films generate major interest -- Helms told THR that he loved The Puffy Chair when it came out -- but those same mid-budget, focus group-written projects that they had turned down are now extinct, suddenly making the brothers' films one of the top destinations for stars looking to stretch their usual roles.

"The $40 million film is over. There's no more middle class," Duplass said. "Reaganomics has happened in the filmmaking industry. We've got your upper class and the lower class, and Jay and I are very, very happy to occupy the lower end of things and we have a very healthy filmmaking career there and as of now, we have no plans to go anywhere else."

That said, they may be sticking to their budgets, but that doesn't mean they're remaining stagnant. Mark produced and starred in the quirky time travel film Safety Not Guaranteed, which was a hit at Sundance and South by Southwest, and they just premiered their latest film, another sibling rivalry story called The Do-Deca Pentathlon at the latter festival. Then there is the acting -- Mark will romance Elizabeth Banks in the upcoming dramedy Welcome to People, and he still has his regular duty on The League. It's a busy life, but it's a rare one, too, as Duplass is fully in control of his destiny.